1. Field of the Disclosure
The disclosure relates in general to a method and apparatus for positioning a mobile device, and more particularly to a seamless and mixed method and apparatus for positioning a mobile device.
2. Description of the Related Art
Global Positioning System (GPS) is a system which locates the longitude and latitude coordinate information of an object globe-wide by using the satellite. The GPS is cheap and easy to access, and has better positioning efficiency in outdoor open field. However, the GPS still has some disadvantages like expensive hardware cost and time delay in first time positioning. Besides, due to existing restrictions, the GPS normally has poor or interrupted reception at high building, tunnel or indoor space. Thus, how to precisely position the user's position in an indoor environment has become an issue attracting wide discussion and study. Wherein, the method for positioning a user in an indoor environment by using the radio frequency (RF) signal is provided.
Examples of the positioning methods using the radio frequency signal such as the wireless network triangulation method and the wireless network pattern matching method normally are involved with the characteristic values or parameters such as time of arrival (TOA), angle of arrival (AOA) or the intensity of radio frequency signal. Wherein, the wireless network triangulation positioning method locates the user's position according to the distance between the user and many access points (AP) through mathematical or physical principles.
Besides, the wireless network pattern matching method locates the user's position through the comparison of characteristic values between the user's location and many access points. However, as the signal intensity decay mode is not easy to construct and the signal intensity is unstable, positioning drift may easily occur to the above positioning methods using the radio frequency signal, and such occurrence would generate illogical user moving paths. Besides, the above methods cannot effectively position 3D movements in a multi-story building.